We examined the structure of the myosin light chain domain in three known conformational states. A combination of crystallographic and electron microscopic results from the literature, and our own spectroscopic experiments, were combined to elucidate myosin's conformation in various biochemical states. Using the resources of the Computer Graphics Laboratory, we determined that the two light chain domains of a single myosin molecule were separated by a minimum of ~80 angstroms when both heads are bound to actin in strongly-bound states. This placed important constraints on our data, and allowed us to construct a novel model for force maintenance and the latch state in smooth muscle.